Dental tool



15a. SKINNER. v

DENTAL TOOL! APPLICATIQN FILED FEB. 6. m9.

Patented J 27, 1920,

UNITED STATES PATENT OFFICE.

PERRY n. SKINNER, or AMSTERDAM, new Yon DENTAL TOOL.

Specification of Letters Patent. Patented Jan; 2'7, 1920,

Application filed February 6, 1919. Serial No. 275,306.

To all whom it may concern:

7 Be it known that I, PERRY SK uNER, a citizen of the United States,residing at Amsterdam, in the county of Montgomery and State of NewYork, have invented cer- .tain new and useful Improvements in DentalTools, of which the following is a specification.

This invention relates to angle attachments for dental handpieces.

Heretofore in the detachable securlng of a tool to an angle attachmentof the kind referred to the tool has been held in operative position bymeans which become unequally worn in use, resulting in thewabbling ofthe tool during operation, and eventually in the dropping of the toolfrom its securing means' The unequal wear of the parts is attributedmainly to the fact that the, tool is held in place by slides, swinglngplates or the like which cover and bear upon only a portion of the areaof the bearing surface provided for it on the tool to be held, forinstance upon a part of the wall of a groove formed in the tool. As aconsequence the tool is neither securely nor evenly held, and in itsrapid long-sustained rotation in use the imperfect holding permits ofthe development of inequalities in the holding medium which naturallyincrease with the use of the tool.

The ob]ect of my inventlon 1s to provlde means whereby a tool mayaccurately be secured to an angle attachment of the character referredto in operat ve posltlon and maintained firmly in such position for anindefinite per od of use in a manner to prevent unequal wear on theparts, and which shall be of a construction to permit of the rapid andeasy securing of a tool in place for use or of its removal whenrequired.

Having the above object in view the invention consists of thetool-attaching means having the novel features of construction andarrangement of parts substantially as hereinafter described and claimed.

The preferred form of embodiment of the I invention is illustrated intheaccompanying drawing in which;

Figure 1 is a longitudinal sectional view of an angle attachment fordental handpieces having combined therewith my'improved means forsecuring a tool in operative position, a tool being shown securedtherein; i 1

Fig. 2 is a top plan view showing by dotted lines the locking means inpositionto engage a tool l Fig. 3 is a perspective view of the lockingplates removed from-the parts withwhicl'r they are combined in use,showing by full lines the positions assumed to secure a tool,

and by dotted lines the positions of the plates when a tool is released;and

Fig. f is a side elevation of a bur having the shank thereof so formedas to, adapt-itto be engaged by the locking plates.

In this drawingl represents thehead of a dental :handpiece-into one sideof which is introduced and secured atubular revoluble sleeve2 which hascombined therewithany suitable means for rotating it. Projecting intothe sleeve at the'inner end thereof is a h1g3 which is of a size' andshape to fit accurately into the recess 4 formed in one side of the endof the shank 5 of a tool, in order that when'the shank is introducedinto-the sleeve the tool and sleeve maybe caused to rotate in unisonwith no play between the parts.

The tool, which is herein shown as a bur,

is formed'with a cylindrical shank of a size to have a close sliding fitwith the interior of the sleeve, and is provided a short distance fromone end with a circumferential groove (3 for the reception of thelocking means by which the tool is operatively held when introduced intothe sleeve. 'The lengths of the lug 3 and of the recess 4 are such thatwhen the lugabuts against theinner end of the recess the shank of thetool projectsbeyond the side of thehead through an opening therein adistance to 'bring'the inner groove to secure the tool are in contactthroughout their entire lengths except where thevare cut away forthereception of that P01131011 of the shank of the tool which {isreduced in groove 6. r

The respective meeting edges of the plates are provided at the partswhirh when in looking position are adjacent to the shank of the tool,with curved indentations 7 and 8 of such form and size that when theplates diameter by the formation of the a are moved to enter the grooveand are in conq handle 11 by means of which it may be swung to enter orbe removed from the groove.

The plate 8 is connected to the plate 7 by means of a link 12 joined tothe lates by pivotal connections. The juncture between the link and theplate 7 is a short distance from the screw or pin on which the plate'ispivoted, while that between the link and the plate 8 is near the outerend of such plate. As a consequence of the described means of connectingthe parts when the plate 7 is swung on its pivot the plate 8 is movedlongitudinally, being maintained in place and guided in its movements bya way formed between the outside face of the head and the inner face ofthe plate 9. The point at which the link 12 is attached to the plate 7is at such a distance from the pivotal point of the plate that the plate8 is moved inward and its curved indentation brought to register withthat of the plate 7 when the latter plate assumes a locking position inthe groove of the tool and the inner faces of the locking platescontact. In order that the swinging of the locking plate 7 on its pivotmay not be interfered with by contacting with the edge of the plate 8,the latter is made of a tapering form as shown, for a greater part ofits length, there being however such a comparatively wide surface of theplate preserved where it bears on the wall of the groove as to aflord asubstantial sustaining surface.

From the foregoing the locking operation --.will be clearly understood.l/Vhen a tool is to be introduced the locking plates are moved to exposethe opening in the side of the head provided for the reception of theshank of the tool. The tool is then introduced in position to bring thelug 1n the interior of the sleeve into the recess in the end of the tooland with the end of the head. When the partsare in this position theplates are moved by means of the handle to bring their inner edges intocontact at which time the indented portions of the plates will enter thegroove in the shank of the tool and closely confine the reduced portionof the shank, effecting a locking of the tool in place by close fittingparts which permit of no lost motion tending to uneven wear ordistortion. It is particularly to be noted that the locking of the toolin operative position in a manner to prevent vibration of the tool inoperation is due to the fact that the locking plates furnish a bearingor sustainingsurface which extends entirely around the tool, instead ofa hearing or holding means extending only partially around the tool ascontemplated by devices for the purpose as heretofore made.

I claim;

1. A device. of the kind described comprising a hand-piece having a toolsocket, and means for locking and. sustaining a tool consisting of aplurality of freely movable plates adapted to contact and be separatedprovided in their meeting edges with indentations for receiving theshank of a tool.

2. A device ofthe kind described comprising a hand-piece having a toolsocket, and locking and sustaining means consisting of plates movable tocontact and be separated and provided in their meeting edges withindentations adapted to receive the shank of a tool, and means forconnecting and moving the plates simultaneously.

3. A device of the kind described comprising a hand-piece having a toolsocket, and means for locking and sustaining a tool consisting of aplurality of freely movableplates arranged on diiferent sides of thesocket and movable to enter and be removed from the socket.

4. A device of the kind described comprising a hand-piece having asocket therein for receiving a tool, means for locking and sustaining atool consisting of a plurality of freely movable plates arranged ondifferent sides of the socket and movable to enter and be removed fromthe socket, and means for moving the plates simultaneously.

5. A device of the kind described com-' prising a hand-piece having atool socket a tool having a circumferential groove adapted to enter thesocket, and a plurality of freely movable plates, the plates beingarranged on different sides of the socket and being movable to enter orbe removed from the groove in the tool.

6. A device of the kind described comprising a locking and sustainingmeans consisting of two plates movable to contact and be separated, eachplate being provided in its edge with an indentation adapted to receivethe shank of a tool, one of the plates being pivotally mounted and'theother being slidable, and a link pivotally connected to the partswhereby they are caused to move in unison.

7. A device of the kind described comprising a locking and sustainingmeans consisting of two plates movable to contact or be separated, eachplate being provided in its edge with an indentation adapted to receivethe shank of a tool, one plate being provided With an operating handleand beingpivotally mounted and the other being movable longitudinally ina sustaining Way, and a link pivotally connected to the plates wherebythey are caused to move in unison.

In testimony WhereofI aflix my signature.

PERRY R. SKINNER.

